The grain-harvesting combine includes a header, which cuts the crop and feeds it into a threshing rotor. The threshing rotor rotates within a perforated housing, performing a threshing operation of the grain from the crop directed thereinto. Once the grain is threshed it falls through perforations in the housing onto a grain pan. From the grain pan the grain falls through a set of upper and lower sieves that are known as the cleaning shoe. The sieves vibrate and/or oscillate causing clean grain to fall through for the collection of the grain and the removal of the chaff or other debris. The cleaning fan blows air through the sieves to discharge chaff toward the rear of the combine. Crop residue such as straw from the threshing section proceeds through a straw chopper and out the rear of the combine.
Combine harvesters that do not have a side slope compensation feature experience increased grain loss when operating on an incline. Gravity causes the grain to shift resulting in excessive loading on the downhill side of the cleaning shoe, which results in increased losses and a lower overall machine capability and capacity. There are several different types of side hill leveling systems that include various levels of performance, complexity and cost. Systems exist that level the entire machine, level the entire cleaning system within the combine or level the individual cleaning elements. There are also systems that induce side motion into the dynamics of the cleaning system to prevent the excessive loading on the downhill side of the machine. Existing three-dimensional shake systems either have limited performance capability or are complex.
What is needed in the art is a cost effective, economical to operate, three-dimensional shake system.